1. Field of the Invention
This invention relates generally to identification of IP flows in a network employing any form of Layer 3 or Layer 4 compression.
2. Description of Related Art
As the Internet has gradually become an integral part of everyday life, the number of Internet users has constantly increased. Recent estimates place the number of users worldwide at over one billion. To compound the problem, the Internet has also experienced a tremendous increase in the amount of traffic per user. As streaming video, peer-to-peer networking, and other high bandwidth applications become the norm, the burdens placed on the underlying network architecture increase exponentially. Consider, for example, the increase in bandwidth from the typical 56 kilobit/second modem used around ten years ago to an average 5 megabit/second DSL connection presently used. In less than ten years, the bandwidth of the average connection available to the end user has increased close to one hundred times.
Despite the massive increases in the amount of users and traffic, a slowing of the growth of the Internet does not appear to be in sight. In developing countries, Internet access is viewed as a sign of progress. On the other hand, for those who currently have access to the Internet, the reliance on the Internet is constantly increasing. For example, users often run web-based applications as a replacement for local applications or download high-quality movies rather than renting a DVD. Countless other uses of large amounts of bandwidth are available or currently being developed.
Although these signs of progress are encouraging to most, service providers face a difficult decision. When designing the congestion management systems, service providers did not contemplate the use of the Internet for streaming video, peer-to-peer applications, and other high bandwidth uses. As a result, when a large number of users run high-bandwidth applications, the best effort architecture frequently experiences congestion, thereby interfering with the user experience.
These problems are particularly salient in the context of mobile networks, where bandwidth is even more limited. Mobile networks are seeing a gradual transformation from voice-only services to data or mixed voice-data services. As per-user bandwidth requirements have increased, the burdens placed on the mobile network architecture have also increased.
Service providers, particularly mobile network service providers, must therefore decide between several options: continue providing best effort service; increase bandwidth and essentially become a transport “utility”; or sell application-specific services based on the requirements of the individual users. Service providers view the first two options as unsatisfactory, as users are dissatisfied with best effort service, while indiscriminately increasing bandwidth would result in additional costs to the service provider with no corresponding increase in revenue. Selling application-specified services, on the other hand, would allow users to pay for the services they desire to receive, while eliminating the need for the service provider to exponentially increase bandwidth.
In order to sell application-specific services, however, service providers must first modify the underlying network architecture to identify and gather information about applications. In the radio portion of mobile networks, the use of per-application traffic management is especially critical, as bandwidth is limited due to the inherent restrictions of radio frequencies. Consequently, mobile operators have started to deploy deep packet inspection (DPI) appliances to help identify applications not only for the purpose of billing, but also to perform traffic management based on the identified application.
In existing mobile network architectures, however, DPI elements are located such that they are unable to effectively manage radio frequencies, as information pertaining to the mobile base station is removed by the time the packets encounter the DPI element. In order to effectively monitor and manage per-application usage, DPI elements would need to be moved to a location in the network that provides visibility of both the end user and the mobile base station.
Placing the DPI elements in these locations, however, requires DPI elements to deal with mobility aspects of the network. More particularly, mobile networks utilize compression schemes to optimize data transmitted over the radio interface. While compression minimizes the amount of data sent over the radio portion of the network, it also removes IP flow information required by the DPI element to effectively identify applications and perform per-application processing.
Accordingly, there is a need for a device that identifies applications associated with data packets where the packet may be compressed. Furthermore, there is a need for an in-line device that identifies applications associated with data packets subject to a compression scheme, such as Robust Header Compression (ROHC) or Compressed Real-Time Transport Protocol (cRTP).
The foregoing objects and advantages of the invention are illustrative of those that can be achieved by the various exemplary embodiments and are not intended to be exhaustive or limiting of the possible advantages which can be realized. Thus, these and other objects and advantages of the various exemplary embodiments will be apparent from the description herein or can be learned from practicing the various exemplary embodiments, both as embodied herein or as modified in view of any variation that may be apparent to those skilled in the art. Accordingly, the present invention resides in the novel methods, arrangements, combinations, and improvements herein shown and described in various exemplary embodiments.